"Steve’s extraordinary vision and leadership saved Apple and guided it to its position as the world’s most innovative and valuable technology company,” said Art Levinson, Chairman of Genentech, on behalf of Apple's Board. “Steve has made countless contributions to Apple’s success, and he has attracted and inspired Apple’s immensely creative employees and world class executive team. In his new role as Chairman of the Board, Steve will continue to serve Apple with his unique insights, creativity and inspiration."

Remembering Steve Jobs

Here's the resignation letter to the board:

To the Apple Board of Directors and the Apple Community:

I have always said if there ever came a day when I could no longer meetmy duties and expectations as Apple's CEO, I would be the first to let you know. Unfortunately, that day has come.

I hereby resign as CEO of Apple. I would like to serve, if the Boardsees fit, as Chairman of the Board, director and Apple employee.

As far as my successor goes, I strongly recommend that we execute our succession plan and name Tim Cook as CEO of Apple.

I believe Apple's brightest and most innovative days are ahead of it.

And I look forward to watching and contributing to its success in a new role.

I have made some of the best friends of my life at Apple, and I thank you all for the many years of being able to work alongside you.

Steve

In after hour trading Apple shares fell 5 percent.

Jobs is 55-years old and has been fighting pancreatic cancer for several years. He has been on medical leave since January 17.

Jobs has appeared at at least two Apple events in San Francisco since being on leave. The last time he was on stage in front of the Apple faithful was in early June. He looked gaunt and thin at every event, but that had become the new normal for the high tech giant.

He also attended a high power dinner with high tech types and Pres. Barack Obama in mid-February.

His last appearance in public was when he surprised people who turned out for Cupertino's city council meeting on Tuesday, June 7 with his pitch to build a massive new campus.

As for Apple's new CEO, Tim Cook has the support of the Apple board.

"The Board has complete confidence that Tim is the right person to be our next CEO," said board member Levinson. "Tim’s 13 years of service to Apple have been marked by outstanding performance, and he has demonstrated remarkable talent and sound judgment in everything he does."

Apple said as COO, Cook was already responsible for all of the company’s worldwide sales and operations, including end-to-end management of Apple’s supply chain, sales activities, and service and support in all markets and countries.